NEET2015PhysicsWork, Power and EnergyActual
A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is:
Options
- Am k 2   t − 1 2
- Bm k   t - 1 2
- C2 m k   t - 1 2
- D1 2 m k   t - 1 2
Correct answer
A. m k 2   t − 1 2
Step-by-step solution
( aligned & F v= constant = k & So , & mdv dt v = k & vdv = k m dt & v ^2 2 = k m t & v = 2 k m t aligned ) Now, ( aligned & F= mdv dt & = m 2 k m 1 2 t ^ - 1 2 & = mk 2 t ^ - 1 2 aligned )